This invention relates generally to heat exchanger method and apparatus, and more particularly to heat exchanger method and apparatus of the counterflow, formed tube air inlet and outlet manifold type, with improved outlet manifold air flow control.
In prior art heat exchangers of the above counterflow, formed tube type, as cooling air flows from the air flow passages in the heat exchanger core and into the air outlet manifolds, it suffers a sudden change of direction, and pressure drop, causing a reduction in core heat exchange capability. Such heat exchangers also lack uniformity of air flow distribution through the passages in the heat exchanger core. In heat exchangers of this type as the air enters the air outlet manifolds, at low velocity, there is lack of uniformity of temperature distribution throughout the manifolds, thus developing temperature gradients between the manifolds and the heat exchanger core, causing thermal stresses, resulting in cracking, and splitting of the heat exchanger core.
Prior art heat exchangers are illustrated in the following U.S. Pat. Nos. 1,313,518 to Clark; 1,914,077 to Cluchey; 2,511,084 to Shaw, 2,819,045 to Pearse, Jr., et al; and 2,875,986 to Holm.